Gunpowder

gunpowder, any of several low-explosive mixtures used as propelling charges in guns and as blasting agents in mining. The first such explosive was black powder, which consists of a mixture of saltpetre (potassium nitrate), sulfur, and charcoal. When prepared in roughly the correct proportions (75 percent saltpetre, 14 percent charcoal, and 11 percent sulfur), it burns rapidly when ignited and produces approximately 40 percent gaseous and 60 percent solid products, the latter mostly appearing as whitish smoke. In a confined space such as the breech of a gun, the pent-up gas can be used for propelling a missile such as a ... (100 of 992 words)